The invention relates to an apparatus for exposure control/focus adjustment for a camera, and more particularly, for such apparatus in which an exposure control and a focus adjustment operation of a camera is driven from a single rotating drive source.
An apparatus for exposure control/focus adjustment for a camera is disclosed, for example, in Japanese Laid-Open Patent Application No. 93,409/1985 in which part of an exposure controlling cam which drives the exposure control is formed with a detent for engaging with a focus adjusting mechanism so that a focus adjustment can be performed by simultaneously locking the focus adjusting mechanism and stopping the rotating drive source, and the detection of rotation of the drive source is switched subsequently to shift from the focus adjustment to the exposure control operation, followed by returning the exposure controlling cam to its initial position.
In such an apparatus, the rotating drive source must be stopped temporarily when shifting from the focus adjustment to the exposure control operation in order to reverse the direction of rotation. This requires a certain length of time until the drive source can respond, resulting in a long time lag from a shutter release to the actual initiation of an exposure process. Accordingly, a rotating drive source having a faster response is required, presenting a problem in respect of the increased expense of a camera. Another problem results that a compelx electrical circuit is required for controlling the rotation of the drive source in the forward and the reverse direction.